Apparatus for converting hydrocarbons



M. P. YOUKER APPARATUS FOR CONVERTING HYDROCARBONS March 7, 1939.

Original Filed Sept. 11,

Patented Mar. 7, 1939 UNITED STATES PATENT OFFICE APPARATUS FORCONVERTING HYDRO- CARBONS Malcolm P. Youker, Bartlesville, Okla.,assignor to Phillips Petroleum Company, Bartlesville, Okla., acorporation of Delaware 5 Claims.

My invention relates to gas conversion processes, and more particularlyto improvements in apparatus for converting normally gaseoushydrocarbons by a method of the kind disclosed in my Patent No.1,800,586, dated April 14, 1931. The present case is a division of myapplication Serial No. 481,318, filed September 11, 1930, (Patent No.2,027,460, dated January 14, 1936) and the present application should beconsidered in conjunction with said Letters Patent, as Serial No.481,318 is a continuation in part of the application which resulted insaid patent.

In said Patent No. 1,800,586, there is disclosed a process of convertingnormally gaseous hydrocarbons into` normally liquid hydrocarbons by rstsubjecting a stream of gaseous hydrocarbons to a temperature in excessof 750 F. while under a pressure in excess of 500 pounds per squareinch, and after the conversion is effected in this way, the resultingmixture is fractionated to produce a fixed gas fraction, a gasolinefraction, and a third fraction intermediate between the fixed gas and.gasoline fractions, the third fraction being recycled or processed in asimilar treatment.

In the continuation in part application, Serial No. 481,318, I havedisclosed and claimed improvements in said process, and in thisvdivisional application, I lay claim to the apparatus described andillustrated in said continuation in part application.

The primary purpose of the present invention is to provide an apparatushaving great flexibility in order that it may be used for convertinghydrocarbon gases alo-ne or mixtures of hydrocarbon. gases andhydrocarbon liquids, with or Without the recycling of gases and/orliquids produced in the process.

With the foregoing objects outlined and with other objects in view whichwill appear as the description proceeds, the invention consists in thenovel features hereinafter described in detail, illustrated in theaccompanying drawing, and more particularly pointed out in the appendedclaims.

The figure illustrates diagrammatically in side elevation, one form ofapparatus: including my improvements.

Referring to the drawing, l designates a furnace through which pipes ortubes, hereinafter referred to, are passed, for the purpose of heatingfluids flowing thro-ugh such conduits. 2, 3, 4, 5, 6 and 'l designatecylindrical closed vessels used for separating gases and/or vapors fromliquids. Pipe lines in which the condensation of materials undergoingtreatment takes place, are passed through condensers 8, 9, I0 and II.Bubble trays I2 are disposed in rectifiers or fractionating columns I3and I4, and in an absorber tower I5.

Hydrocarbon gases, in either liquid or vapor 5 phase, will be introducedinto the apparatus through a pipe line I6 in which is interposed acontrol valve I'I, a pump I9, and apressure reducing valve I8. The pipeline I6 extends through the furnace to the separator 2, and the partsI'I 10 and I9 are positioned anterior to the furnace, while the pressurereducing valve I8 is located between the furnace and the separator forthe purpose of reducing the pressure on the heated fluid before thelatter enters the separating cham- 15 ber.

Liquid collecting in the separator 2 is: discharged through a line 20leading to the medial portion of the iirst rectifying' column I3. Acontrol valve 2I is interposed in the pipe. 20

Liquid collecting at the bottom of the fractionating column will bedischarged through a pipe 22 and a valve 23 into the fractionatingcolumn I4.

Liquid which will collect in the bottom of the column I4 can bedischarged through a pipe 24 25 and a valve 25 into the separator l, andliquid or tar accumulating in the latter will be discharged therefrom bya pump 26 through a pipe 21 and a cooler (not shown).

Vapors and permanent gases will separate from the liquid in theseparator 2, and will be discharged by way of a pipe line 28, throughcon.- denser 8 and into the separator 3. Vapors and gases will pass fromthe top of column I3 by way of pipe 29 through condenser 9 intoseparator 4. 35 Vapors and gases will also pass from the top offractionating column I4 by way of a pipe 30 through condenser I0 intoseparator 5. Vapors will pass from the top of separator 'I by way ofpipe line 3| through condenser I I into separator 6.

Gases, such as excess hydrogen, hydrogen sulde, nitrogen and helium,separate from heavier gases and vapors in the separator 3, and aresubstantially constantly vented from the: system through a pipe 32 inwhich is interposed a back pressure valve 33. Similar gases may bevented from the top of separator 4, through a pipe 34 provided with aback pressure valve 35.

If any such gases should remain with heavier materials when the latterreaches the separator 5, these gases may be vented through the pipe 36and valve 31 arranged at the top of the separator 5 For the purpose ofmaintainingV sub-atmospheric pressure within the separator 6, a gas ventpipe 38 1s arranged at the top of this chamber, and is provided with avacuum pump 39. This pump will also maintain sub-atmospheric pressurewithin the separator 1, as the pipe line 3| connecting these separatorsdoes not have any valves interposed therein.

Liqueiied gases, heavier than hydrogen, hydrogen sulde, nitrogen andhelium, which accumu- Liquid accumulating in the bottom of separa-V tor6 may be discharged by means of a pump 46 through a pipe 41 having acontrol valve 48.

If desired, some of the above mentioned fixed gases can be recycled fromthe top of the separator 3 by means of a pipe line 50 having acompressor 49 and a control valve 5I interposed therein. y

A conduit 53 having a valve 52 interposed therein, connects the upperportion of the separator 2 to the pipe v5I), so that the compressor 49may be used to force gases and vapors from the separator into the pipeI6 at a point between the pump I9 and the furnace.

Gases from the top of the separator 4 can be introduced into the pipeline 5D posterior to the compressor 49 by means of a compressor 54interposed in a pipe 55 having a control valve 59.

A reflux liquid can be delivered from the bottom of the separator 4Vinto the top of the rectif-ler I3 by means of a pump 51 interposed inthe pipe 58, for the purpose of preventing gasoline and heaviermaterials from entering the pipe 29.

Liquid can also be delivered from the bottom of the separator 5 into thetop of the rectier I4 by means of a pump 59 interposed in a conduit 60to prevent material heavier than gasoline entering the pipe 30.

For the purpose of heating'the bottom of the column I3, a pump 6I isinterposed in a pipe 62, extending from the bottom of the column I3through the furnace and back into the lower portion of this column. Asimilar device, 63, 64, is employed for heating the bottom of the columnA pipe 65 having a valve 66 leads from an extraneous supply ofhydrocarbon liquid to a pump 61. Some'or all of this hydrocarbon liquid'can be forced by the pump 61 through a pipe 68 having a valve 69,intorthe pipe IB, at a point between the pump I 9 and the furnace.

Another pipe 18 having a valve 1|, leads from the outlet of the pump 61into the top portion of the absorber I5, and a conduit I2 having a valve13 connects the bottom of the absorber to the pipe I6 at a point aheadof the pump I9.

Heavy oil, such as fuel oil or gas oil can thus be delivered directlyinto the pipe I6 posterior to the pump I9, or can bepassed through theabsorber into the pipe I6 at a point anterior to the pump I9. l

' Gas entering the pipe I6 can be introduced into the absorber through apipe 'I4 having a valve 15, and some of the up-flowing gas can beabsorbed by the heavy oil flowing downwardly through the absorber, andthen the mixture of oil and gas may be introduced into the pipe I6through the pipe 12. Gases escaping absorption in the absorber I5 aredischarged through a pipe 16 having a back pressurevalve 11, the latterpermitting the absorber to be operated under super-atmospheric pressure.

VA hydrocarbon liquid, which may be a heavy oil, gas oil or crude oil,may be introduced into the pipe I6 at a point between the furnace andthe separator 2, by means of a pump interposed in a pipe line 18 havinga control valve I9.

A pipe 8| in which are mounted valves 82, 83 and 9|, connects into thepipe 18 on the suction side of the pump 80, and connects into the pipe55 on the suction side of the pump 61 for the purpose of introducingliquid produced in the systeminto the pipe I 6, either ahead or afterthe furnace, and also into the absorber I5. A pipe having an interposedpump 86 and a valve 81 leads from the bottom of the rectifier I4 intopipe 8|, and another pipe 88 provided with an interposed pump 89 and avalve 90 leads from the bottom of separator 6 to the pipe 8|. Obviously,the pumps 86 and 89 can be used to deliver heavy oils from the rectifierI4 or the separator 6 into either the pipe 65 or pipe 18.

A pipe 92 having a valve 93 is connected to the pipe 85 at a pointbetween the pump 86 and valve 81, so that liquid withdrawn from thebottom of the fractionating column I4 may be delivered to storage.

From the foregoing it will be apparent to those skilled in the art thatgases may be introduced into the inlet of the heating tube I6 throughthe inlet end of this pipe, or by means of the pipes 4I or 56, or gasmay be fed into the heating coil, absorbed in the oil by means of thepipe 12, or admixed with oil introduced from an extraneous sourcethrough pipe `65, or produced in the system and coming from therectifier I4 or separator 6. Furthermore, a hydrocarbon liquid can beintroduced into the pipe I6 by means of the pipe 18, either from anextraneous source or from the rectifier' I4 or separator 6. Hence, avariety of operations can be carried out by the present apparatus, forthe polymerization of gases, the cracking of oil, the distillation ofoil, or for combinations of these operations.

In my parent application Serial No. 481,318, I have disclosed howhydrocarbon liquids may be made from hydrocarbon gases by two methodswhich are closely related, and both of which may be practiced in thepresent apparatus. These methods of gas conversion may be usedseparately or may be combined in the same process, and the apparatusdisclosed may be used to carry out either one of these methods or thecombination of the two. For the purposes of clarity, I will describethese methods separately.

Some of the hydrogen may be removed from hydrocarbon gases, and theremaining hydrogen content be simultaneously recombined with the carboncontent of such gas to form liquid hydrocarbons, or carbon may be addedto hydrocarbon gases and combined with excess hydrogen contained thereinto form a hydrocarbon liquid. The former case would be de-hydrogenationof the hydrocarbon gases, and the latter case may be calledcarbonization of hydrocarbon gases.

My apparatus may be used to de-hydrogenate gas in the following manner:

Hydrocarbon gas in either liquid or gaseous state will be delivered bypump I9 through the pipe I6, and will be heated therein to a temperaturepreferably between 700 and 1000 F. while held under a pressure in excessof 500 pounds per square inch. I have found that good results may beobtained at a temperature around 875 F. under pressures between 2000 and3000 pounds per square inch, and a good conversion from gases to liquidsresults. After the conversion of part of the gases to liquid has takenplace in the pipe I6, cold hydrocarbon liquid is introduced into thepipe I6 through the pipe I8 in order to cool the mixture of gases andliquids down to such a temperature, say 400 to 600 F., that only gaseswhich are more volatile than gasoline will remain in the vapor orgaseous phase; the cooled converted gases and liquid, together with theadded hydrocarbon liquid then flowing into se-parator 2. Gases andvapors which are more volatile than gasoline will then flow through pipe28 and condenser 8 into separator 3. As the material passing through thecondenser 8 will be cooled, a mixture of liquid and gas will bedelivered into the separator 3. The material which remains in a gaseousstate after passagev through the condenser will be vented from thesystem through the pipe 32. Some of it may be recycled if desired bymeans of the compressor 49.

Liquid collecting in the separator 3 can be withdrawn therefrom andrecirculated through the pipe I6, and thereby through the process, bymeans of pump 4D.

Liquid trapped in separator 2 will, of course, consist mainly ofgasoline and heavier hydrocarbons, but as only a rough separation takesplace in this separator, it will also contain material more volatilethan gasohne, and this liquid will be delivered through the pipe 20 intothe rectier I3. 'I'he latter makes` a relatively sharp separation betwengasoline and heavier hydrocarbons on the one hand, and material lighterthan gasoline on the other hand, and this lighter material dischargedthrough pipe 29, is cooled in the condenser 9, with the result that amixture of iiquid, gases, and vapors ows into the separator 4. Some ofthe liquid collecting in this separator is forced by the pump 51 intothe top of the column !3 for reux purposes, with a view of preventinggasoline and heavier material from entering the pipe 29. Some of thisliquid can also be recycled by means of pump 42 and pipes 43 and 4IGases leaving the top of the separator 4 can be vented from the systemthrough the pipe 34, or some of them may be recycled by means ofcompressor 54 and the pipes 55 and 5D.

Liquid consisting of gasoline and heavier hydrocarbon material isdischarged from the bottom of column I3 through the pipe 22, leading tothe medial portion of the column I4, and gases and vapors pass from thetop of the latter' column through the pipe 38 and condenser I0 into theseparator 5 where the gasoline is accumulated. Any gases remaininguncondensed are discharged from the separator 5 through the pipe 36.Some of the gasoline accumulated in the separator 5 is forced by thepump 59 into the top of the column I4 for reilux purposes, so thathydrocarbon material heavier than gasoline is prevented from enteringthe pipe 39. Gasoline is withdrawn from the system through the pipe 44.

Liquid which is heavier than gasoline, that is, fuel oil and gas oil,may be withdrawn from the bottom of column. I4 through the pipe 92tonstor.- age, or some or all of it may be recycled by means of the pump86.

The vacuum distillation unit, consisting of the separators. 'I andcondenser II and accessory pumps, pipe lines, etc., is conventional andis for the purpose of separating gas oil or lubricating oil from fueloil, and as before stated, gas oil accumulating in the bottom of theseparator 6 may be recirculated by means of the pump 89 to either thepipe I6 or pipe 78.

Through manipulation of valves I8, 2| and 33, superatmospheric pressure,say to- 2000 to 3000 pounds per square inch may be maintained in theseparators 2 and 3, and in the pipe lines accessory to these separators.By manipulating valves 23 and` 35, pressure preferably between 400 to700 pounds per square inch, sufficiently high to condense in condenser 9all vapors passing through pipe 23, will be maintained in the column I3,separator 4 and accessory pipe lines. By means of the valve 3l,atmospheric pressure will preferably be maintained in the column I4,separator 5 and connecting pipe lines.

By the method of operation just described, natural gas or constituentsof natural gas may be charged to the apparatus through the pipe IS, anda portion of the same will be converted into synthetic crude oils andgases. The apparatus is so designed that after conversion has takenplace, the converted material may be separated into the followingfractions: Permanent gases, some of which are vented from the systemthrough the pipes 32, 34 and 36, and some of which may be recycled bymeans of compressors 49, 54 or both; gases which are heavier than` saidpermanent gases, b-ut more volatile than gasoline, and which may berecycled by means of pumps 4Q, 42; motor fuel or gasoline dischargedthrough the pipe 44; and heavier oils, such as gasl oil or fuel oilwhich may be withdrawn from the system through pipes` 92 and 41, orwhich may be recycled by means of pumps 86 and 89.

Gas delivered to the apparatus ordinarily contains certain permanentgases which, if not vented from the system, would, in a short time, llthe system and prevent the apparatus from operating. Hydrogen is alsocontinuously evolved within the system, and if such gases are not ventedfrom the apparatus, they will interfere with the operation. For thisreason, I have provided the vent pipes 32, 34 and 36 for substantiallyconstantly venting such gases from the system.

Furthermore, by means of my apparatus, the material produced which isheavier than these permanent gases and more volatile than gasoline, maybe readily recycled, as they are maintained under high pressure at alltimes, and preferably in liquid form in order that the recirculation maybe accomplished economically. When gas only is supplied from anextraneous source to the apparatus, a considerable quantity of hydrogenwill necessarily be vented from the system.

If it is desired to simultaneously treat hydrocarbon gases andhydrocarbon liquids, fuel oil or gas oil may be introduced into the pipeI6 from the various sources heretofore referred to, to supply carbonwith which to combine the excess hydrogen contained in the gas, in whichcase hydrogen need not be vented from the system, and only suchpermanent gases as are inadvertently introduced into the system with thecharging stock will be separated from the other materials and ventedfrom the system. Liquids which contain a. higher percentage of carbonthan is contained in gasoline, can, of course, be introduced into thesystem either through the pipe 65 or pipe 18. In the event that crudeoil should be introduced, it is passed through the pipe 18, andthegasoline content in this oil will be` distilled therefrom, due to theadmixture of the oil with the heated material from the pipe heater, andsuch gasoline will be separated from the other products in thefractionating system. Of course, the gas oil and fuel oil contained insuch crude oil will again enter the pipe I6 as a recirculated liquid,coming either from column I4 or separator 6. This is an indirect way ofintroducing fuel oil or gas oil into the system when crude oil only isavailable for the purpose.

It has been found desirable in some cases to cool any liquid which isheavier than gasoline, and which is introduced into the pipe I6, and toinitially use this heavy oil as an absorbent to absorb constituents ofnatural gas, and subsequently introduce the mixture of heavier thangasoline liquids and lighter than gasoline constituents thus producedinto the pipe I6. Obviously, the absorber I5, with inter-connectinglines shown, may be used for this purpose.

' As stated in my Patent No. 1,800,586, and parent application SerialNo. 481,318, I do not propose to limit the present apparatus to thetreatment of natural gas, but may use it to convert other hydrocarbongases such as those produced by the cracking of heavy oils, and thetreatment of other carbonaceous materials. In some cases, I will, in themanner described herein, use the apparatus to add carbon contained inheavy oils, such as fuel oil or gas oil, to hydrocarbon gases resultingfrom cracking natural gas under comparatively low pressures and hightemperatures.

While I have disclosed what I consider to be a preferred embodiment ofthe invention in such manner that the same may be readily understood bythose skilled in the art, it is manifest that changes may be made in thedetails disclosed, Without departing from the spirit of the invention,as expressed in the claims.

What I claim and desire to secure by Letters Patent is:

1. In an apparatus of the character described, a furnace, a heating tubefor conveying a stream of hydrocarbons through the furnace, a rstseparator connected to the outlet end of said tube and in which gasesand vapors separate from liquid, a second separator for separatinglighter gases from heavier ones, a first pipe leading from the top ofthe rst separator to the second separator, means for cooling gaseousmaterial flowing through the pipe' for condensing a portion of saidmaterial before the latter flows into the second separator, valvecontrolled means for venting uncondensed material from the topl of thesecond separator, means for returning condensate from the secondseparator to the intake of the heating tube, a rectifying column, a pipefor leading liquids from the bottom of the first mentioned separatingchamber into the medial portion of the rectifying column, means forheating the bottom portion of the rectifying column, a conduit fordischarging gaseous material from the top of the rectifying column, athird separator receiving the material from said conduit, a cooler forcooling said material as` it flows through the conduit for condensing aportion of said material before it enters the third separator, means forreturning a portion of the last mentioned condensate into the top of therectifying column for reflux purposes, means for returning anotherportion of said last mentioned condensate to the intake of the heatingtube and means for withdrawing liquid hydrocarbons from the rectifyingcolumn.

2. In an apparatus of the character described, a furnace, a heating tubefor conveying a stream of hydrocarbons through the furnace, a rstseparator connected to the outlet of said tube and in which gases andvapors separate from liquid, a second separator for separating lightergases from heavier ones, a first pipe connecting the top portion of thei'lrst separator to the second separator for conveying gases and vaporsfrom the flrst separator to the second separator, means for cooling thelast mentioned gases and vapors as they flow through the pipe forcondensing a portion of these materials before they ow into the secondseparator, valve controlled means connected to the top of the secondseparator for venting uncondensed gases from the top of the secondseparator, a second pipe provided with an interposed compressor andvalve connecting said valve controlled means to the inlet of the heatingtube for recycling some of said uncondensed gases, a third pipeconnected to the bottom portion of the second separator for withdrawingcondensate from said second separator, and a fourth pipe connected tothebottom portion of the first separator for discharging liquids from, thelatter, a valve controlled conduit connecting the upper portion of thefirst separator to the second pipe anterior to the compressor of thelatter for returning gases and vapors directly to the intake of theheating tube without passing them through said cooling means and secondseparator.

3. In an apparatus of the character described, a furnace, a heating tubeextending through the furnace, a separator connected to the outlet endof said tube and in which gases and vapors separate from liquid, meansfor discharging gases and vapors from the upper portion of saidseparator, a rectifying column, a pipe connecting the lower portion ofthe separator to the medial portion of the rectifying column, means forfeeding liquid from the lower portion of the rectifying column in aconned stream through the furnace and back into said rectifying column,another separator, a conduit connecting the upper portion of therectifying column to the last mentioned separator and having a condenserinterposed therein for feeding a mixture of vapors and gases from therectifying column and for condensing a portion of the same beforedischarging the mixture into the last mentioned separator, a pipeconnecting the lower portion of the last mentioned separator to the topportion of the rectifying column for returning some of said condensateinto the rectifying column for reflux purposes, a valved vent pipeleading from the top of the last mentioned separator for dischargingnormally gaseous material from the last mentioned separator, fluidconveying means connecting the vent pipe to the inlet end of the heatingtube, and a liquid discharge pipe leading from the bottom portion of therectifying column.

4. In an apparatus of the character described, a furnace having aheating tube therein for conveying a stream of hydrocarbonstherethrough, a first separator connected to the outlet end of saidheating tube to receive the eflluents therefrom and for separating gasesand vapors from liquids, a second separator for separating light gasesfrom heavy gases, a pipe connecting said separators, a condenserinterposed in said pipe for cooling and condensing ar portion of thegases flowing therethrough to said second separator, a pipe connectingsaid second separator with the intake of said heating tube for returningcondensate thereto from said second separator, a valve controlled pipeleading from said second separator for venting uncondensed gasestherefrom, a rectifying column having a pipe connecting a medial portionthereof with said rst separator for co-nducting liquids therefrom tosaid rectifying column, a pipe leading from the bottom of saidrectifying column through said furnace and back into said column to heatthe bottom portion thereof, a third separator, a valve controlled pipeleading from said third separator for venting uncondensed gasestherefrom, a pipe connecting the third separator With the top of saidrectifying column for the discharge of gaseous material therefrom, acondenser interposed in the last mentioned pipe for cooling andcondensing a portion of said gaseous material, a pipe connecting thebotto-m of said third separator with the top portion of said rectifyingcolumn for the introduction therein of reflux condensate from said thirdseparator, a pipe connecting said third separator with the intake ofsaid heating tube for returning condensate thereto from said thirdseparator and a pipe for withdrawing liquid hydrocarbons from saidrectifying column.

5. In an apparatus of the character described, a furnace, a heating tubefor conveying a stream of hydrocarbons through the furnace, means forfo-rcing normally gaseous lwdrocarbons into the inlet end of said tube,separate means for forcing a normal liquid hydrocarbon into the inletend of said tube, a rst separator connected to the outlet of said tubeand in which gases and vapors separate from liquid, a second separatorfor separating lighter gases from heavier ones, a first pipe connectingthe top portion of the first separator to the second separator forconveying gases and vapors from the first separator to the secondseparator, means for cooling the last-mentioned gases and vapors as theyow through the pipe for condensing a portion of these materials beforethey ow into the second separator, valve controlled means connected tothe top of the second separator for venting uncondensed gases from thetop of the second separator, a second pipe provided with an interposedcompressor and valve, connecting the top portion of the second separatorto the inlet of the heating tube for recycling some of said uncondensedgases, a third pipe connected to the lower portio-n of the secondseparator and leading to the inlet of the heating tube for conveyingcondensate from the second separator to the inlet of the heating tube,means interposed in the third pipe for forcing condensate therethrough,and a valve interposed in the third pipe for controlling the oW ofcondensate therethrough.

MALCOLM P. YOUKER.

